1. Field of the Invention
The present invention relates generally to the field of robotics and more particularly to mobile self-balancing robots.
2. Related Art
Telepresence refers to the remote operation of a robotic system through the use of a human interface. Telepresence allows an operator of the robotic system to perceive aspects of the environment in which the robotic system is located, without having to physically be in that environment. Telepresence has been used, for example, by doctors to perform medical operations without being present in the operating room with the patient, or by military personnel to inspect a bomb.
Robotic systems that provide telepresence capabilities are either fixed in a particular location, or provide a degree of mobility. Of those that provide mobility, however, the forms tend to be close to the ground and built on wide platforms with three or more legs or wheels for stability. These systems, in short, lack a generally upright human form, and accordingly, an operator cannot perceive the remote environment from a natural upright perspective with the normal range of motion one would have if actually present in the remote environment.
Some two-wheeled self-balancing robotic systems have been developed in recent years. One such system is controlled by a human rider. Absent the rider, the system merely seeks to keep itself in an upright position with a feedback loop that senses any tilting from this upright position and rotates the two wheels to restore the upright position. A user standing on the system may control movement by leaning back and forth. This causes a tilt away from the upright position, which is interpreted as a command to move in the direction of the tilt.
One concern with self-balancing robots pertains to safety during power disruptions. Power disruptions include the sudden loss of power, such as when a power cord is cut, a loss of sufficient power, such as when a battery system runs low transient power spikes, and the like. Power disruptions can cause the robot to lose balance and damage itself, damage other property, and cause injury to people. Most power disruptions occur without warning. In the case of battery systems, it can be difficult to estimate the available energy that a battery system will be able to produce, and therefore the battery system may run low without warning.